Housing for drive gearing in a dual wheel assembly



June 20, 1950 c. s. ASH 2,512,050

HOUSING FOR DRIVE GEARING IN A DUAL WHEEL ASSEMBLY INVENTOR- CH/ELjQf. 45H

ATTORN EY HOUSING FOR DRIVE GEARING IN A DUAL WHEEL ASSEMBLY Original Filed June 11, 1942 c. 's. ASH

June 20, 1950 2 Sheets-Sheet 2 w A C;

INVENTOR C/l/l LE5 S. flSl/ Y M ATTORNEY Patented June 20, 1950 UNITED STAT ES P TENT or rice HOUSTLNG FUR DRIVE GEARING IN A-DUAL WHEEL ASSEMBLY Charles S. Ash, Milford," Mich.

Continuation of application Serial No. 446,621,

June 11, 1942. Thistapplication August 24, 1945,

Serial No. 612,443

1 Claim.

withthe invention, thesame being realized and attained by means of the instrumentalities and combinations pointed out in the appended claim.

The invention consists in the novel parts, constructions,arrangements, combinations, and improvements herein shown-and described.

The acco-mpanying drawings, referred to herein and constituting apart hereof, illustrate one-embodiment of the invention, and together with the description, serve to explainthe principles of the invention.

This application is acontinuation of my application Serial No. 446,621, filed June 11, 1942, now abandoned.

Of th drawings:

Figure 1 is a vertical sectional view of adual, driven, differential, dirigiblewheel assembly embodying the present invention;

FigureZ is a cross-sectional view taken along the line 22 of Figure 1; and

Figure 3 is .a detail plan View of certainof the differential means. of the invention takenalong line 33--of.Figure 2.

The present invention has for an object the provision vof animproved driven dual wheel assembly in which the individual wheels are capable of relative rotation and protective and lubricant retaining housingmeans are provided about the differential driving mechanism betweenv the wheels which cooperate to provide thrust bearing means for taking axial thrusts in either direction. Referring now in detail to the embodiment of the inventionshown by way of example in the :accompanying drawings, and referring particularly to Figure 1, the live axle shaft lil of an automotive vehicle ismounted in the hollow axle housing II, it being understood that th members of the dual wheel assembly herein shown and described are duplicated at the opposite end of the axle housing II on the other side, of the vehicle. A spherical knuckle lZis formed integral with housing l l at its end, and seated in recessed portions at the top and bottom of the knuckl ar bearings 13 in which are journalled the reduced end portion of king pins [4. The outer thickened por-' tions of king pins M are seated in circular apertures in yoke arms I! and maintained therein by cap plates it which are firmly secured to the yoke arms.

The yoke arms. I! .at -their outer ends carry by means of .cap screws IS th hollow stub spindlev 20, and a steering arm 2! .is connected to the upper yoke-arm in order to impart steering move ment tospindle 2G by means of any conventional and suitable steering gear mechanism. Within the spindle 20 is positioned the live stub shaft 22 to. furnishpower to the :dual wheels of the assembly, said shaft receiving its power froinrthe live axle I!) through asuitable universal joint, which in Figure 1 is indicated by the numeral.

23 and is shown as a Marmon-Herring-ton construction.

A cylindrical driving sleeve.25. of greater diameter than the spindle '20 is positioned over the spindle and is rotatably mounted thereon by means of tapered roller bearings 26 and 21. The

inner bearing 26 is seated by its inner race against.

asubstantial shoulder 28. of-the spindle 2B, and by its outer race against an. inwardly extending annular shoulder 29 of the driving sleeve 25. The other or outer tapered roller bearing 2'! has its outer race seated against a second inwardly extending. annular shoulder til of the driving sleev A retaining nut 32 threaded on the-end of spindle it with an interposed washer 33 engages themher race of bearing 21 and holds th bearings and drivingsleeve in place upon th spindle. A lock'nut 34 may also be threaded on the end of the spindlev firmly positioned for the function of anti-friction-sand anti-thrust. between the spindle 20 and the driving sleeve 2.5. A driving connection is established between the live stub shaft and the driving sleeve 25 by means of the member 36 which has. an annular portion 31 secured to the sleeveiby means of bolts 3.8 and a cylindrical portion 38 which has inwardlyv projecting teeth to mesh with the end of the stub shaft which is formed as a broad face pinion gear.

The outer Wheel ,hub. Allis journalled on the outer end of driving sleeve. 25 for relativ rotation withlrespectthereto, and the outerwheel 4| is supported-on the .hub ill and secured for rotation therewith by-meansof pins 52 which extend through avfiangepcr-tion l-7% of the hub and into a suitable aperture the Wheel. The pins 42 are maintained in place b a cov r plat 44 whichextends over the end of the stub shaft and drivingsleeve assembly, and is-secured to flange 43 of the outer wheel hub ill by a plurality of cap screws ill. The hub 49 abuts against the annular portion Lil-of the member 35 which maintains the hub-in place upon th driving sleeveandacts as a thrust bearing between the members.

The inner wheel hub :50 is journalled on the The bearings. 26 and 27 are thus inner end of driving sleeve 25 for relative rotation with respect thereto, and supports the deeply inwardly dished inner wheel The hub 50 has a flange portion 52 which abuts against an integral outwardly extending flange portion 53 of the driving sleeve 25, whereby the hub is maintained in position and a thrust bearing efiected. A plurality of pins 54 extending through flange 52 and into wheel 51 near its inner periphery secures the wheel to its hub for rotation therewith. Each of the vehicle wheels 4!, 5| is provided with a suitable pneumatic tire supporting rim 55 and means of any convenient type for demountably mounting the tire rim on the wheel.

The differential driving means between the driving sleeve 25 and the wheel 4|, 5! of the assembly may illustratively comprise a spider ring 60 which is fixed to driving sleeve 25 at a position between the inner and outer wheel hubs for rotation therewith. A plurality of circumferentially spaced cap screws 6| pass through apertures provided in the spider ring and are securely threaded into driving, sleeve 25 in the thickened central portion thereof provided by the shoulder 30. Other longer cap screws 52 are similarly positioned in the spider ring 68 and driving sleeve 25 and have rotatably mounted about the outer portion of their length the helical pinion idler gears 63 of the differential means. Each such helical pinion idler gear is in mesh with a pair of worm pinion gears 65, which are positioned on either side of the idler gear axially of the driving sleeve 25. The worm pinions 65 are rotatably mountedin transverse hangers 66 which are an integral part of spider ring 60. The ends of the inner and outer wheel hubs 40 and 50 adjacent spider ring 60 are formed with helical teeth 61, as shown in Figure 3, to form a helical worm gear as an integral part of each hub, and the helical teeth 67 are in mesh with the worm pinion gears 65.

The advantage of the differential means of the present invention embodying the worm pinion gears 65 and helical pinion idler gears 63 over the more conventional type of difierential wherein bevel pinion gears only are utilized isin the fact that the former is more sluggish in its operation. That is, the worm pinion type diiferential provides more resistance to the movement of one wheel by the movement of the other through the worm pinion gears 65 and the helical pinion idler gears 63, due to the wedging or sliding action in the mesh of the gears. Such resistance is desirable and necessary in a wheel assembly such as that of the present invention, where it may occur on uneven or slippery surfaces that one of the wheels of the assembly may have sufiicient traction with the ground while the other has little or none.

When such conditions are encountered with the assembly of the present invention ample power may still be continuously transmitted to the wheel with the better traction although some power is lost in the ineffective rotation or slipping of the wheel without traction. The more conventional type of diiferential, such as is shown in the prior patent to Rumpler, German No. 466,062, however, would transmit substantially the whole power to the ineffective wheel and result in the stalling of the vehicle.

The torque transmission from one wheel to the other through the helical ring gear teeth 67, the spiral pinion gears 65 and the helical pinion idler gears 63 of the assembly of the present invention varies with the helix angle given to the spiral teeth of the spiral pinion gears 63. The helix angle of these gears is indicated by the angle A in Figure 3 of the accompanying drawings and is illustratively shown as 30. Thus a smaller helix angle will 5 result in a greater torque transmission to one of the wheels by turning the other, and a greater helix angle will result in a lesser torque transmission. The helix angle given to the spiral pinion gears 65 may be as high as 45 and this construction results in the transmission of relatively little torque from one wheel to the other, or stated another way, results in a comparatively free difierential action between the individual wheels of the dual wheel assembly. The helix angle chosen may be a smaller one, depending upon the freedom of the differential action desired, but the angle can in no case be smaller than a critical angle beyond which the worm pinion gears become non-reversible. By nonreversible is meant a condition where full torque is transmitted to one wheel by the turning of the other, and in this condition the wheels are as effectively locked against the desired differential action as though they were bolted together, as is the case with non-independently rotatable dual wheel structures. pletely the advantages of the independently rotatable dual wheel structure and is, therefore, to be avoided.

The helix angle for the worm pinion gears 65 in accordance with the present invention is, therefore, greater than the critical angle at which said worm pinions become non-reversible, and it has been found that the angle should not. be smaller than 20 in order to obtain a differential action between the wheels. Thus, a helix anglev between the critical angle and an angle of may be chosen, depending upon the freedom with which it is desired for the differential action to occur, and various helix angles of less than 45 result in difierential action which is more or less limited.

Thrust bearing and differential gear protection means are provided on the dual wheels 4| and 54,-

ion idler gears 63 and the other members of the differential. At their adjacent peripheries the flange members 10, II have thickened portions 12 and 13 respectively, on which are formed opposed parallel radial surfaces 12' and 13 respectively which, with an interposed bearing ring M, form thrust bearings between the dual wheels and serve to properly space the worm pinion gears 65 and the helical pinion idler gears 63. The portions 12, it further have formed thereon outward facing bearing surfaces 93 and 99 respectively which are inclined with respect to the axis of the wheels, a 45 angle of inclination being illustrated and preferred.

An annular ring 15 of V-cross section encircles the enlarged bearing portions 12, 13 of the wheels, and is formed with grooves adjacent the flange members 10 and H in which sealing rings 76 are positioned in order to prevent the loss of lubrieating material from the differential housingand the ingress of dust and other harmful substances. The ring 15 is formed in two halves, as may be seen in Figure 2, which are adjustably secured together by bolts 18 and nuts 19. By the engage-- ment of the inclined faces [00 and ll of ring Such an efiect destroys com 15 with the cooperatingly inclined faces 98 and 99 of the enlarged bearing portions 12 and 13 an effective achieved adapted to resist the axial thrust of wheels 4| and 5| away from each other.

Braking means for the dual wheel assembly are provided connected to the driving sleeve 25 so that the retarding action may be transmitted to the individual wheels through the differential mechanism. Thus braking effort is exerted upon both wheels of the assembly, and the advantages which have been described for the differential of the present invention are utilized to the same extent in braking the vehicle as in driving it. As illustratively embodied these means comprise an inwardly dished annular brake drum supporting member 99 which is bolted to an outwardly radially extending radial flange 9| integral with bearing flange 53 of driving sleeve 25, whereby the supporting member 90 rotates with the driving sleeve. A brake drum 92 is carried by supporting member 90 for rotation therewith, and a brake band 93 is carried by brake anchor member 94 to be expanded by any suitable and conventional means against the inner surface of brake drum 92.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claim without departing from the principles of the invention and without sacrificing its chief advantages.

What I claim is:

A dual wheel assembly comprising, in combination, a driven sleeve, a pair of side by side wheels having hubs rotatably mounted on the sleeve, differential gearing means between the wheels interconnecting the wheels and sleeve for driving the wheels, said wheels having adjacent annular diametrally adjustable bearing is flange portions surrounding the differential gearing means and abutting to form a housing about said means, said portions having opposed plane, annular, radially extending bearing surfaces adapted to abut each other and other bearing surfaces inclined with respect to the axis of said wheels intersecting said first surfaces, and a bearing ring having inclined converging surfaces to engage said other bearing surfaces, said radial and inclined surfaces providing bearings between the wheels for axially directed thrust in either direction.

CHARLES S. ASH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 233,145 Demarest Oct. 12, 1880 882,574 Moukos Mar. 24, 1908 1,942,512 Lee Jan. 9, 1934 1,979,598 Ash Nov. 6, 1934 1,994,719 Lichty Mar. 19, 1935 2,022,141 Morgan Nov. 26, 1935 2,075,563 Alden Mar. 30, 1937 2,135,568 Durham et al Nov. 8, 1938 2,182,560 Higbee Dec. 5, 1939 2,239,674 Frederickson Apr. 29, 1941 2,284,357 Ash May 26, 1942 2,303,031 Dusevoir Nov. 24, 1942 2,341,755 Ash Feb 15, 1944 2,355,133 Ash Aug. 8, 1944 2,387,382 Ash Oct. 23, 1945 FOREIGN PATENTS Number Country Date 466,062 Germany Oct. 1, 1928 

